1. Field of the Invention
The present invention relates to generation and verification of alternative data having a specific format.
2. Discussion of Related Art
An encrypting system for information security not only ensures confidentiality of data, but also provides a service such as data integrity or authentication. Although a two-way encryption scheme is used for the confidentiality of the data, a one-way encryption scheme may be used for a service such as integrity or authentication.
These encryption schemes may change the format of digital data. For example, when plaintext constituted of a numeric type of character string is encrypted using a block encryption algorithm such as an advanced encryption standard (AES), ciphertext may include a character string rather than a numeric form. The change of this data format is the same even in the one-way encryption technique.
Recently, rules or industry requirements that force the protection of personal information have increased. The personal information may be stored or managed by a database (DB) and transmitted through a communication network. Here, the personal information is handled as data represented in a specific format. In particular, a method of protecting personal information by storing or transmitting alternative information corresponding to the personal information without directly handling the personal information serving as a protection target is provided. In this case, when data is processed by merely applying a one-way or two-way encryption scheme for protection of the personal information, there is a problem in that an existing DB or a communication network does not reflect a change in the format of processed data.
For this, format-preserving encryption and decryption are disclosed in U.S. Pat. No. 7,864,952. Although the format-preserving encryption scheme to be applied in two ways is disclosed in the aforementioned U.S. Pat. No. 7,864,952, a format change problem of the one-way function is not mentioned.
In addition, U.S. Patent Application Publication No. 2009/310778 discloses a token system for protecting personal information using alternative information. The aforementioned U.S. Patent Application Publication No. 2009/310778 only discloses a method of protecting the personal information using the alternative information without mentioning a format change problem of the alternative information.
Accordingly, there is a need for a method of generating and verifying alternative data corresponding to information serving as a protection target without requiring a design change of an existing data processing system.